EASC 108 Lecture Notes - Lecture 12: Spectroscopy, Late Heavy Bombardment, Orbital Period
29 Mar 2017
School
Department
Course
Professor
Document Summary
4th planet from sun (1. 5 au), 7th largest world. Mars has similar obliquity (25 ) to the earth. Interaction with solar tides shows current core is not entirely solid radius. Modeling of fe-ni-s materials at high pressure indicate core may still be completely liquid. Oldest solar system solids, in chondrites, have ages 4. 57 ga. Differentiation locks all the tungsten (w) in mars" core. W levels > chondrites: tungsten produced after core formation, implies core formation in 13 2 myr. 4. 5 ga very old rock indicates stable crust already existed. Northern and southern hemispheres of mars very distinct: Theories for dichotomy: giant impact (earth/moon idea) several large basins early plate tectonics. Buried impact basins in the northern hemisphere now mapped. Before burial, the n and s hemispheres were indistinguishable in age: rules out earth-style plate tectonics. N hemisphere is thinly covered of the s hemisphere. Mantled by 1-2 km of material (sediments and volcanic flows)
